1. Field of the Invention
This invention relates to a process of producing a sustained release preparation containing indomethacin or niomethacin.
Indomethacin is the commercial name of 1-(4-chlorobenzoyl)-2-methyl-5-methoxy-indolyl-3-acetic acid. Niomethacin is the commercial name of 1-nicotinoyl-2-methyl-5-methoxy-indolyl-3-acetic acid.
2. Description of the Prior Art
Indomethacin and niomethacin are known as therapeutically effective substances, which are used in the control of inflammatory diseases and are contained as active ingredients in various pharmaceutic preparations. They are effective in preventing and inhibiting the formation of granulation tissue and are valuable in the treatment of arthritic, rheumatic and similar diseases which are responsive to a treatment with antiinflammatory agents.
A treatment with the conventional pharmaceutic preparations containing indomethacin or niomethacin and consisting, e.g., of tablets or capsules requires several intakes a day. Most patients requiring a treatment with antiinflammatory agents are old and often take also various other medicaments. For this reason it is desirable to reduce the number of intakes to one intake a day, if possible. On the other hand, the treatment requires a certain serum level of the active ingredient to be maintained.
Besides, the antirheumatic drugs of this kind produce secondary effects in the stomach. In the treatment with indomethacin, said secondary effects have caused up to 20% of the patients to discontinue the therapy.